I work at a car accessory retailer and we install Sterling, Toad and Sigma systems.
The Toad AI606 is a great entry level alarm with all the features you need. I personally chose the Sigma S30 as the module is more compact and the remote is, in my opinion more period for the age of the vehicle.
Either way you can't go wrong, the Toad is a great choice, we literally never have trouble with them, very much a tried and tested system.